Connectors



May '9, 1967 United States Patent 3,319,214 CONNECTORS Donald N. Sewell, Acton, Mass., assignor to Dielectric Products Engineering Company, Inc., Raymond, Maine, a corporation of Michigan Filed July 12, 1965, Ser. No. 471,192 Claims. (Cl. 339-911) This invention relates to connectors for electrical transmission lines and, more particularly, to inner conductor connectors for RF coaxial transmission lines.

It is a primary object of this invention to provide a connector for connecting two tubular inner conductor components of a coaxial transmission line which is simpler and less expensive to manufacture than those connectors heretofore available. Another object of this invention is to provide a novel and improved connector structure for use in a coaxial transmission line which is inexpensive to form and finish, is simple to assemble together to complete the connection between tubular conductor components and obviates difficulty and damage that results from mismatch of the connector and conductors. A further object of the invention is to provide in such a connector assembly an arrangement which withstands expansion and contraction of the conductor without damage to either and Without significant impairment on the electrical connection between the conductor and the connector. In particular, it is an object of this invention to provide a plurality of longitudinally similar segments which combine to form a single connector assembly arranged to resiliently engage and support two inner conductor components and to include latch elements for securing the inner conductor to the connector assembly.

The invention features a plurality of longitudinally similar segments of electrically conductive material which are assembled together to form a tubular connector element. The assembled connector element includes a circumferential recess at each end over which the ends of two cooperating tubular conductor members,.typically inner conductor elements of a coaxial transmission line, are fitted, one at either end of the connector assembly, so that the inner-surfaces of the conductors overlie the outer surface configuration of the recesses and act to hold the plurality of connector segments in assembled tubular form. In a particular embodiment, the assembly further includes a central circumferential groove which is adapted to receive a disc insulator support and an auxiliary circumferential groove disposed in each recess. The connector assembly further includes an annular resilient electrically conductive member disposed in each auxiliary groove which in the conductor-connector assembly engages the inner surface of the conductor which provides the electrical connection between the conductor and the connector assembly. In the preferred embodiment, the annular resilient members disposed in the auxiliary circumferential grooves are small closely wound coil springs of silver-plated beryllium copper. The connector assembly further includes one or more resilient latch members which are disposed in axially extending depressions in the recess at one of the ends of the connector assembly and which cooperate with a lance section of the conductor to lock that conductor element securely in place on the connector assembly.

Other objects, features and advantages of the invention will become apparent as the following description of a particular embodiment of the invention progresses, in conjunction with the drawing, in which:

FIGURE 1 is a side view with parts broken away of a coaxial cable inner conductor support assembly constructed in accordance with the invention;

FIGURE 2 is a sectional view taken along the line 2-2 of FIGURE 1;

FIGURE 3 is a sectional view taken along the line 3-3 of FIGURE 1; and

FIGURE 4- is a perspective view of a segment of the connector assembly employed in the structure shown in FIGURE 1.

With reference to the drawing and, more particularly, FIGURE 1, there is shown a portion of a coaxial line having an outer conductor 10 and inner conductor elements 12 and 14. A connector assembly 16 connects the inner conductor elements 12 and 14 and that assembly is supported in coaxial position within the outer conductor 10 by insulating disc member 18. The connector assembly 16 is composed of two identical copper segments 20, 22, of arcuate cross section, the general configuration of each of which being formed in a forging or hammering operation from plate stock. As indicated in FIGURE 2, the thickness of the connector segments is substantially uniform throughout, the thickness of the body of the connector segments being substantially the same as the thickness of the segment in the base of a groove. The formation of the connector segments is formed by a hammering or forging operation which shapes the malleable conductor metal into the desired configuration without removal and waste of metal as results from a machining operation. These conductor segments are substantially completely formed in this manner.

Each connector segment has formed in its outer surface at either end thereof recesses 24, 26 (section of reduced radius) a central groove 28 and an auxiliary groove 30, 32 disposed in each recess 24, 26, respectively. The outer end of each recessed section 24, 26 is tapered as at 34. Also, in the recess 26, there is formed a second or further longitudinally extending recess 36 which is adapted to receive a resilient locking element 38. These two connector segments are semi-circular in configuration and have mating surfaces 40 which, when in contact with one another, provide a tubular connector assembly. The only machining operation employed in forming these segments is a milling operation that forms surfaces 40.

After the segments are assembled in tubular form, springs 44, 46 are disposed in the auxiliary grooves 30 and 32. Each spring is of a diameter slightly greater than the depth of the groove so that it protrudes above the surface of the recess 24, 26, respectively, when positioned in the groove. Each spring consists of approximately one hundred turns of silver-plated beryllium copper wire. These springs act to hold the connector segments together. The open end of the tubular conductor elements 12, 14 are then positioned over the recesses 24 and 26 as indicated in FIGURE 2 towards abutting contact with radial recess end surfaces 48 so that the inner surfaces of the conductor elements are in frictional engagement with the springs 44, 46, respectively, and the multiplicity of contacting surfaces complete electrical circuits between the conductor elements 12 and 14 and the connector segments 20, 22. Where compensation for axial movement of conductors is not necessary, a simpler connector construction may be utilized in which the connector segments 20, 22, are formed without the auxiliary grooves 30, 32, and the springs 44, 46 omitted so that the connector segments are held together by frictional engage ment of the inner surface of the tubular connectors with the surfaces of the recesses 24, 26. It will be noted that in either case, the inner conductor elements 12 and 14, when in position, assist in maintaining the segments of the connector assembly in their tubular relationship.

The resilient latch clips 38 disposed in the longitudinally extending recesses 36 may be fastened in place by pins or rivets 50 or the clips may be modified in readily apparent manner, as for example, so that each latch 38 is frictionally secured in the recess 36. The clip has a latch end 52 which protrudes above the surface of the spring element 46, and formed adjacent the end of the inner conductor component 14 is a slit tab with a portion thereof depressed so that it forms a lance 54 having an end 56 inside of the tubular conductor. The lance end 56 engaging the protruding end 52 of the clip 38 when the conductor is positioned on the recess with the end of the conductor element in engagement with the radial end surface 48 of the recess locks the conductor element on the connector assembly. In this position, the conductor element 14 cannot be removed from the connector assembly unless a tool is inserted through the aperture at the end of the lance to depress the protruding ends 52 of clip 38 to move that end out of engagement with the lance end 56. Thus, the connector assembly is secured to the conductor element merely by sliding of the connector into the tubular conductor element and engaging the conductor lances with the connector latches. This assembly is particularly useful where the coaxial line is to be disposed vertically as it enables the connector assembly to be handled as a unit with a conductor element.

The recess 24 has its auxiliary groove 30 positioned a substantial distance from the radial surface 48. A typical distance is 0.3" which affords compensation for thermal expansion or contraction of the conductor elements 12 and 14 where such conductor elements are up to thirty feet in length. Otherwise, the joint between the connector assembly and the conductor element 12 is similar to the joint between conductor element 14 and the connector assembly, the electrical connection being accomplished through engagement of the resilient spring member 44 with the inner surface of the conductor element 12 and the surfaces of groove 30 without any frictional contact with the surface of recess 24. The tapered ends 34 of the recesses facilitate the insertion of the ends of the conductor elements onto the recesses of the connector assembly.

Thus, the invention provides a connector assembly which may be manufactured with substantially no machining operations, thus avoiding the cost of such operations both in terms of the waste metal that is generated and the time necessary for the performance of such operations. Further, electrical contact is provided, not with individual contact fingers, but with a multiplicity of contact elements in the form of the turns of the springs. The connector assembly is arranged with tapered noses so that the assembly of the tubular conductors over the ends of the connector assembly is facilitated. The tubular configuration of the connector assembly reduces the problems of matching the impedances of the connector assembly and the conductor elements.

While a particular embodiment of the invention has been shown and described, various modifications thereof will be apparent to those skilled in the art and, therefore, it is not intended that the invention be limited to the disclosed embodiment or to details thereof and departures may be made therefrom within the spirit and scope of the invention as defined in the claims.

What is claimed is:

1. A coaxial line connector assembly comprising a plurality of longitudinally identical forged segments of electrically conductive metal, each said segment having substantially uniform cross-sectional thickness throughout its length and having a recessed surface at each end of substantial length so that said connector segments when assembled together form a tubular element with a circumferential recess at either end adapted to receive in overlying relation the inner surface of a tubular conductor element, a circumferential groove in each said recess, an annular resilient electrically conductive member disposed in each groove for providing an electrical connection between the tubular conductor element and the connector assembly, and a further recess in each segment located between said recessed surfaces for receiving an insulator support for positioning said connector assembly coaxially Within a second tubular conductor element.

2. The connector assembly as claimed in claim 1 wherein said resilient member is a closely wound coil spring.

3. The connector assembly as claimed in claim 1 wherein each of said circumferential recesses is tapered to a reduced diameter at its outer end.

4. A coaxial line connector assembly comprising a plurality of longitudinally identical forged segments of electrically conductive metal, each said segments having substantially uniform cross-sectional thickness throughout its length and having a recessed surface at each end of substantial length so that said connector segments when assembled together form a tubular element with :a circumferential recess at either end adapted to receive in overlying relation the inner surfce of a tubular conductor element, a circumferential groove in each said recess, an annular resilient electrically conductive member disposed in each groove for providing an electrical connection between the tubular conductor element and the connector assembly, and a latch element secured in one of said recesses for locking said cooperating tubular connector element against axial movement relative to said connector assembly.

5. A coaxial line connector assembly comprising a plurality of longitudinally identical forged segments of electrically conductive metal, each said segment having substantially uniform cross-sectional thickness throughout its length and having a recessed surface at each end of substantial length so that said connector segments when assembled together form a tubular element with a circumferential recess at either end adapted to receive in overlying relation the inner surface of a tubular conductor element, a circumferential groove in each said recess, an annular resilient electrically conductive member disposed in each groove for providing an electrical connection between the tubular conductor element and the connector assembly, and a longitudinally disposed recess in one end of each of said connector segments, each said longitudinal recess having secured therein a latch spring of U-shaped configuration with a free end disposed above said circumferential recess for locking relationship with a lance on said conductor element when the conductor element is in overlying relation such that said latch spring is held in compression by said conductor element.

References Cited by the Examiner UNITED STATES PATENTS 2,123,631 7/1938 Koehler 33964 2,758,291 8/ 1956 Richards 339205 X 3,070,770 12/ 1962 Mercier 33964 3,089,115 6/1963 Wicks 339177 FOREIGN PATENTS 858,703 1/ 1961 Great Britain.

MARVIN A. CHAMPION, Primary Examiner.

W. DONALD MILLER, Examiner.

JOSEPH H. MCGLYNN, Assistant Examiner. 

1. A COAXIAL LINE CONNECTOR ASSEMBLY COMPRISING A PLURALITY OF LONGITUDINALLY IDENTICAL FORGED SEGMENTS OF ELECTRICALLY CONDUCTIVE METAL, EACH SAID SEGMENT HAVING SUBSTANTIALLY UNIFORM CROSS-SECTIONAL THICKNESS THROUGHOUT ITS LENGTH AND HAVING A RECESSED SURFACE AT EACH END OF SUBSTANTIAL LENGTH SO THAT SAID CONNECTOR SEGMENTS WHEN ASSEMBLED TOGETHER FORM A TUBULAR ELEMENT WITH A CIRCUMFERENTIAL RECESS AT EITHER END ADAPTED TO RECEIVE IN OVERLYING RELATION THE INNER SURFACE OF A TUBULAR CONDUCTOR ELEMENT, A CIRCUMFERENTIAL GROOVE IN EACH SAID RECESS, AN ANNULAR RESILIENT ELECTRICALLY CONDUCTIVE MEMBER DISPOSED IN EACH GROOVE FOR PROVIDING AN ELECTRICAL CONNECTION BETWEEN THE TUBULAR CONDUCTOR ELEMENT AND THE CONNECTOR ASSEMBLY, AND A FURTHER RECESS IN EACH SEGMENT LOCATED BETWEEN SAID RECESSED SURFACES FOR RECEIVING AN INSULATOR SUPPORT FOR POSITIONING SAID CONNECTOR ASSEMBLY COAXIALLY WITHIN A SECOND TUBULAR CONDUCTOR ELEMENT. 